The invention relates generally to providing mitigation of dynamic range overload in radars. In particular, the invention maximizes track and detection ranges when there is overloading or saturating at the radar receiver from clutter or large targets.
Ground clutter and large targets produce large amplitude signals at the radar receiver. If the amplitude of the signals exceeds the dynamic range of the receiver, then the data output from the receiver are unreliable. Subsequent signal processing of the unreliable data further expands the range extent of unreliable data. Under such circumstances, range gates can develop that render the radar effectively blind, thereby precluding detection of a target.
For example, for a single large amplitude scatterer with a length of 100 feet causing receiver saturation for a 10% duty radar, then 20% of all range gates would have unreliable data and be incapable of reliably detecting targets. Thus, a medium pulse repetition frequency (PRF) radar using range ambiguous processing and searching to 100 miles would be blind for 20 miles of the 100 miles even though the length of the target is only 100 feet.
The reason that in this example a single saturating target can have such an adverse influence is that the saturation time is extended by the pulse width of the radar in the receiver causing the loss of 10% of the range space. The subsequent signal processing of the unreliable data stretches by the matched filter producing total of 20% unreliable data.